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Wireless keyboards = boon for hackers

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Wireless keyboards are insecure and hackers can sniff-out every password you type on them.

This is the verdict of a warning posted on Bugtraq by German security outfit Daten-Treuhand. The company has tested Logitech's Cordless Desktop product and outlined how a hacker could intercept a users' keystrokes.

You connect your cordless keyboard to your PC by first pressing a connect-button on the receiver, and then another button on the keyboard. A fixed set of transmit-codes are sent between the receiver and the keyboard until the receiver locks in on the first undistorted code it gets. Keystoke data is then transmitted between the two via RF.

The problem arises because each transmitter/receiver pair does not appear to be hard-coded to match each other, according to Axel Hammer of Daten-Treuhand. "They simply seem to run out of the fab and the customer connects them the first time he is using the set, according to the manual. This leaves the crucial backdoor to connect whatever device you have to whatever receiver you have," he wrote in his alert.

"The receiver waits for 30 minutes after initialising a connect for new devices to sync to them, even if there has been an undistorted reception of at least one sync-code. An attacker is able to sniff the connect-sequence of a victim's device from far and to lock-in to the code of the victim's devices or to take control of a victim's device."

Hammer says that it is possible for the victim and the attacker to read the keystrokes without the victim noticing the attack. And to sniff a connection of wireless devices, all you need is a receiver from the same manufacturer, same model, and by slight modifications it is possible, to extend the range of the receiver to about 30m.

Daten-Treuhand recommends using infra-red devices if you have to go wireless. ®